Oligomyrmex (Aneleus) politus (Santschi)
Minor -
Type location Kenya (Aneleus politus, Santschi,
1914b: 79, illustrated, minor; Consani, 1951: 170, queen);
subspecies nicotianae (as Sporocleptes nicotianae,
Arnold, 1948: 220, illustrated, worker) from Zimbabwe;
minor and queen only described (see Bolton, 1995)
.
Santschi's (1914b) description is at
.
Consani's (1951) description of the queen is at
.
Arnold's (1948) description of nicotianae is at
.
The minor described by Bernard (1952) as villiersi seems
a simple junior synonym of this species - see below. |
There
seems a strong possibility that this could be separable as a
distinct monotypic Genus. Both Arnold (1948: 220) and Bernard
(1952: 240) suggested that was the case. Curiously despite several
collections, from Kenya, Zimbabwe (nicotianae), Guinea (villiersi,
Bernard) and Nigeria (below), there has been no definite finding
of a major morph. Bernard (1952) also refers to numerous
subterranean workers (of Nimbamyrma) having been collected
in Angola. Moreover, the size of the reported queen (Consani,
1951) at TL 10 mm is quite remarkable for the genus Oligomyrmex.
The queen of paetus (above) is TL 4.5 mm, and of perpusillus
arnoldi is TL 3.8 mm. The few descriptions of Oligomyrmex
queens all describe the morphology as similar to that of the
soldier, particularly that the head is rectangular, somewhat
longer than wide. The head of Consani's queen is quite different
(see comparative illustration below), being much more like that
described for Carebara queens, as much wider posteriorly
and at least as wide as long, often wider.
Bolton (1995: 299) refers to Arnold (1952a: 460) as recognising
nicotianae as a subspecies of politus. Consani
(1951) has a note that Arnold, in a letter, synonymized Sporocleptes
under Aneleus. When Arnold (1952a) is examined, however,
this synonymy is justified as -
"Mr William J Brown (Harvard University) has drawn
my attention to the close similarity between Sporocleptes
nicotianae Arn., and Aeneleus politus Sant., .... and
has suggested there probably is a synonymy. He also kindly sent me
a specimen of Aeneleus politus, collected at Blue Post
Hotel, Kenya, and determined by Menozzi".
"A comparison of this specimen with Sporocleptes
nicotianae proves that Sporocleptes must be placed in
synonymy with Aneleus, and that nicotianae may be
regarded as a race of politus, from which it differs as
follows. The head is much less convex transversely, the epinotal
[propodeal] teeth are longer, the sides of the epinotum are
reticulate, the apex of the node of the petiole is wider, and the
colour is much paler. Santschi's figure is inaccurate, as the
membranous extension ventrad of the epinotal spines has been
omitted". |
To
me, all that shows is that the single specimen designated Aneleus
politus by Santschi, the specimens designated S.
nicotianae by Arnold and the specimens designated Nimbamyrma
villiersi, and so-on, are variants of a single pan-African
species. Arnold does not seem to have considered whether or not
his recognition of a new genus was correct and that it was
Santschi who was in error in placing it in Aneleus.
Bolton (1987) refers to the Pheidologeton group of
Myrmicine genera as including Anisopheidole Forel (a
monotypic Australian genus),
Carebara
Westwood, Lophomyrmex Emery (an Oriental, Indo-Australian
genus), Oligomyrmex,
Paedalgus
Forel (queens have TL range 5.4-6.9 mm, HW = HL;with associated
workers TL 1.4-1.6, Bolton & Belshaw, 1993) and
Pheidologeton.
Bolton & Belshaw (1993) considered that the monomorphic Carebara
and Paedalgus possibly could be combined in a single
genus, comparing them with Oligomyrmex which they declared
as having all its known species being dimorphic in the worker.
They noted also that Carebara and Paedalgus differ
from Oligomyrmex in having queens which are far larger
than the minor workers (e.g. Carebara vidua - queen TL 24
mm, minor TL 1.6-2.0 mm).
The wing structure of Consani's queen, however, is typical of a
Pheidologeton-group member, having a closed cell where Rs
joins R. Until further evidence arises to confirm that the queen
described and illustrated by Consani is actually that of politus
the Genus question must remain open. |
Oligomyrmex (Aneleus) villiersi (Bernard)
Minor -
TL 1.8 mm; colour bright yellow, very shiny, with almost no
puncturation or sculpturation other than striated or reticulated
areas on the thorax. No pubescence, short hairs on the appendages;
raised sensory hairs, no more than 4 per segment on the head,
thorax and abdomen. Head gross, very rounded, a little longer than
wide. Occiput scalloped, concave and lightly bordered. Clypeus
large, triangular, median border rectilinear, armed with two
lateral teeth. Mandibles stout, slightly arched, with 4 large
teeth and 2-3 denticles; palps very short. Eyes level with the
base of the scapes, black, miniscule, with 9-11 discontinuous
facets. Antennae slender with the scape not reaching the vertex;
funiculus of 10 segments, only 2-6 wider than long. Thorax
slender, anterior bordered, striated thereafter; generally smooth;
fine reticulation on prosternum; mesosternum and mesopleuron more
so; strong longitudinal striae on metanotal groove. Propodeum
short with two strong teeth, plus two shorter inferior teeth.
Petiole and postpetiole very long and slightly elevated. Gaster
small.
Type location Mt. Nimba, Guinea, two miniors only, from
the north-east forest, leaf litter sifting by Villiers, ix.1946
(as Nimbamyrma villiersi, Bernard, 1952: 241, illustrated,
minor); minor only described (see Bolton, 1995).
Bernard's (1952) description, with his genus definition, as Nimbamyrma,
is at .
|
Nigeria specimens (Pheidologeton species in
Taylor, 1980a: 41). Only a single morph was present in the CRIN
collection, presumed to be a minor. TL 1.87 mm, HL 0.53, HW 0.47,
SL 0.39, PW 0.26
Colour golden yellow. Unsculptured except for slight
reticulation on the lateral mesonotum. Erect hairs relatively long
and sparse. Propodeal spines long, narrow and acute; promesonotal
suture absent; petiole and postpetiole with laterally compressed
nodes.
Found in leaf litter at the Cocoa Research Institute of Nigeria,
Idi Ayunre, by B. Bolton, who determined the generic status
(personal communication, 1976). |
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